Submission #973613

#	Time	Username	Problem	Language	Result	Execution time	Memory
973613		saayan007	Cyberland (APIO23_cyberland)	C++17	20 / 100	3049 ms	527956 KiB

cyberland

#include "bits/stdc++.h"
#include "cyberland.h"
using namespace std;
const char nl = '\n';
 
#include <vector>
 
struct UFDS{
    int n; vector<int> lnk, sz;
    UFDS(int N) {
        n = N;
        lnk.resize(n);
        iota(lnk.begin(), lnk.end(), 0);
        sz.resize(n, 1);
    }

    int find(int a) {
        return (a == lnk[a] ? a : lnk[a] = find(lnk[a]));
    }

    bool same(int a, int b) {
        return (find(a) == find(b));
    }

    void unite(int a, int b) {
        a = find(a); b = find(b);
        if(a == b) return;
        if(sz[a] < sz[b]) swap(a, b);
        lnk[b] = a;
        sz[a] += sz[b];
    }
};

double solve(int N, int M, int K, int H, vector<int> x, vector<int> y, vector<int> c, vector<int> arr) {
    K = min(K, 70);
    vector<pair<int, double>> adj[N];
    UFDS uf(N);
    for(int i = 0; i < M; ++i) {
        adj[x[i]].emplace_back(y[i], c[i]);
        adj[y[i]].emplace_back(x[i], c[i]);
        if(x[i] != H && y[i] != H) uf.unite(x[i], y[i]);
    }
    /* cout << N << " cities" << nl; */
    /* cout << M << " edges" << nl; */
    /* cout << H << " destination" << nl; */
    /* for(int i = 0; i < M; ++i) { */
    /*     cout << i << " : "; */
    /*     for(auto u : adj[i]) { */
    /*         cout << "(" << u.first << ", " << u.second << ") "; */
    /*     } */
    /*     cout << nl; */
    /* } */
 
    double dist[N][K + 1];
    for(int i = 0; i < N; ++i) {
        for(int j = 0; j <= K; ++j) {
            dist[i][j] = -1;
        }
    }

    priority_queue<pair<double, pair<int, int>>> pq;
    dist[0][0] = 0;
    pq.push({-dist[0][0], {0, 0}});
    for(int i = 0; i < N; ++i) {
        if(uf.same(i, 0) && arr[i] == 0) {
            dist[i][0] = 0;
            pq.push({-dist[i][0], {0, i}});
        }
    }
 
    while(!pq.empty()) {
        int a = pq.top().second.second;
        int st = -pq.top().second.first;
        double d = -pq.top().first;
        pq.pop();
        if(dist[a][st] < d || a == H) {
            continue;
        }
 
        for(auto [b, w] : adj[a]) {
            if(arr[b] == 0) {
                dist[b][st] = 0;
                pq.push({-dist[b][st], {-st, b}});
                continue;
            }
            if(dist[b][st] == -1 || d + w < dist[b][st]) {
                dist[b][st] = d + w;
                pq.push({-dist[b][st], {-st, b}});
            }
            if(arr[b] == 2 && st < K) {
                ++st;
                if(dist[b][st] == -1 || (d + w) / 2 < dist[b][st]) {
                    dist[b][st] = (d + w) / 2;
                    pq.push({-dist[b][st], {-st, b}});
                }
                --st;
            }
        }
    }
 
    double ans = -1;
    for(int i = 0; i <= K; ++i) {
        if(ans == -1 || (dist[H][i] != -1 && ans > dist[H][i]))
            ans = dist[H][i];
    }
    return ans;
}

• Subtask 1: 5 / 5
• Subtask 2: 8 / 8
• Subtask 3: 0 / 13
• Subtask 4: 0 / 19
• Subtask 5: 7 / 7
• Subtask 6: 0 / 16
• Subtask 7: 0 / 29
• Subtask 8: 0 / 3